Parameters of fluid responsiveness.

Abstract

On the basis of recent literature, we summarized the new advances on the use of available dynamic indices of fluid responsiveness. Reliability of passive leg raising to assess fluid responsiveness is well established provided that a real-time haemodynamic assessment is available. Recent studies have focused on totally noninvasive techniques to assess its haemodynamic effects with promising results. Presence of intra-abdominal hypertension is associated with false-negative cases of passive leg raising. Use of pulse pressure and stroke volume variations is limited and other heart-lung interaction tests have been developed. The tidal volume challenge may overcome the limitation of low tidal volume ventilation. Preliminary data suggest that changes in pulse pressure variation during this test well predict fluid responsiveness. Growing evidence confirms the good predictive performance of the end-expiratory occlusion test. All these dynamic tests allow selecting appropriate fluid responders and preventing excessive fluid administration. Performance of a mini-fluid challenge may help for the decision-making process of fluid management if other tests are not available. Several new dynamic variables and monitoring techniques to predict fluid responsiveness were investigated in the past years. Nevertheless, further research investigating their reliability and feasibility in larger cohorts is warranted. VIDEO ABSTRACT.